2.5µA, 1% Accurate SOT-23 Comparator and Voltage Reference for Battery Monitoring

The LTC1998 is a micropower comparator and a precision adjustable reference in a 6-pin SOT-23 package that is optimized for lithium-ion low battery detection circuits.

The LTC1998 features a voltage detection circuit with an adjustable threshold voltage and hysteresis. The threshold voltage can be programmed from 2.5V to 3.25V with two external resistors. A 10mV to 750mV hysteresis can be added with a third external resistor.

A proprietary internal architecture maintains 1% threshold voltage accuracy over temperature with low cost 1% external resistors.

A separate power supply pin, VLOGIC, allows the battery-low logic output to operate below the battery voltage, allowing compatibility with low voltage microprocessors without a pull-up resistor. Power supply glitches are eliminated by preventing the cross-conducting current which occurs when the output changes state.

The LTC1998 operates with battery or supply voltages up to 5.5V and its battery-low output is valid for battery voltages above 1.5V.

Applications

* Lithium-Ion Battery-Powered Equipment

* PDAs

* Cell Phones

* Handheld Instruments

* Battery Packs

* Pagers

* Palm Top Computers

* POS Terminals

* High Accuracy Trip Voltage: 1% Max Error using External 1% Resistors

* Adjustable Threshold Voltage and Hysteresis

* Quiescent Current: 2.5µA Typ

* Output Swings Rail-to-Rail

* Thresholds Programmable from 2.5V to 3.25V

* Output State Guaranteed for VBATT ≥ 1.5V

* Low Profile (1mm) ThinSOT™ Package